1. Field of the Invention
At least one embodiment of the invention relates to an implantable defibrillation arrangement.
2. Description of the Related Art
Implantable defibrillators or cardioverters (ICD) have been known and used in clinical applications for a long time, and have been the subject of sustained technical development for decades. This applies to an even greater extent for implantable cardiac pacemakers and the associated electrode leads. Combination cardiac stimulation and defibrillation arrangements, including the electrode leads (ICD electrodes) developed especially therefore, have also become established as a special class of devices on the device market and in clinical applications. Such combination devices are referred to as cardiac pacemakers for cardiac resynchronization therapy with defibrillator, or CRT-D devices.
FIG. 1 shows a schematic depiction of such an arrangement 100 including electrodes implanted in the heart H of a patient. Accordingly, a cardiac stimulation and defibrillation device 110 is connected to the heart H via an electrode lead 120 which comprises three lead branches or electrode supply leads 130, 140 and 150. Each lead branch comprises sensing or stimulation electrodes (which are not depicted individually) on or near the distal end thereof, and lead branch 150 also comprises an elongated defibrillation electrode 160. In the arrangement shown, lead branch 130 is placed in the right atrium, lead branch 140 is placed in the left atrium of the heart H, and lead branch 150 on which defibrillation electrode 160 is installed is placed in the right ventricle (RV).
When a shock is administered, only the shock coil of the RV electrode is switched to a high-voltage potential, while the bipolar sensing and stimulation system remains at the output potential. The supply leads inside electrode lead 120 must therefore be designed with insulating clearances that are resistant to high voltage.
In all of the ICD electrodes known to date, insulating clearances for high voltages must be maintained within the electrode lead, which limits a further reduction of the electrode diameter and prevents the integration of a shock coil onto a CS electrode.